Use of growth hormone or analogues thereof for the treatment of mammals with familial hypercholesterolemia

ABSTRACT

The invention relates to the use of compounds selected from GH, analogues thereof, and GH-releasing compounds, optionally in combination with lipid-lowering agents or therapy, for the preparation of a drug for treatment of mammals with familial hypercholesterolemia of homozygous form.

This application is a 371 of PCT/SE99/01898 filed Oct. 21, 1999, whichclaims the benefits of foreign priority from Sweden Application No.9803623-9 filed Oct. 22, 1998.

BRIEF DESCRIPTION OF THE INVENTION

The present invention relates to the use of biologically activecompounds selected from GH, analogues thereof and GH-releasingcompounds, as lipid lowering agents for the preparation of a drug forthe treatment of mammals with homozygous familial hypercholesterolemia.By the furnishing of a drug comprising compounds selected from GH,analogues thereof and GH-releasing compounds, optionally in combinationwith further lipid lowering treatment, elevated plasma cholesterol inLDLR deficient mammals with familial hypercholesterolemia of thehomozygous form may be treated.

Growth hormone (GH) has pleiotropic effects on cholesterol metabolism.GH stimulates the expression of hepatic low density lipoprotein(LDL)-receptors and the activity of cholesterol 7α-hydroxylase (C7αOH),a key regulatory step in bile acid synthesis. According to the presentinvention it is shown that GH treatment reduces plasma cholesterol inthe situation of homozygous familial hypercholesterolemia as representedby the recently developed LDL-receptor knockout mouse strain.

GH infusion into LDL-receptor knockout mice resulted in a 30-40% reducedplasma cholesterol level. In addition, the reduced enzymatic activitiesof cholesterol 7α-hydroxylase and HMG CoA reductase were normalized. Itis concluded that GH treatment reduces the severe homozygous form offamilial hypercholesterolemia in LDLR-deficient mice. Such therapy givesa beneficial effect in the heavily therapy resistant disease homozygousfamilial hypercholesterolemia, a disorder known to be strongly resistantto lipid-lowering treatment.

In this specification and the appended claims the followingabbreviations are used: C7αOH, represents cholesterol 7α hydroxylase;HMG CoA reductase, represents 3-hydroxy-3-methyl-glutaryl coenzyme Areductase; FPLC, represents fast performance liquid chromatography; GH,represents growth hormone; HDL, represents high density lipoprotein;LDL, represents low density lipoprotein; LDLR, represents low densitylipoprotein receptor; LDLRKO, represents low density lipoproteinreceptor knockout; SDS-PAGE, represents sodium dodecylsulphate-polyacrylamide gel electrophoresis; TNA, represents totalnucleic acid; VLDL, represents very low density lipoprotein.

BACKGROUND OF THE INVENTION

Familial hypercholesterolemia (FH) is a common autosomal dominantinherited disease and is present in heterozygous and homozygous forms.

Heterozygous FH occurs at a frequency of approx. 1:300-500 in thegeneral population. The subjects have type II-A lipid pattern andapproximately twice the normal low-density lipoprotein (LDL) cholesterollevels. Heterozygotes have an increased risk to develop premature heartdisease and their expected life span is reduced 10 to 15 years. FHheterozygotes have a mutation in the gene encoding the LDL receptor.This receptor is located on the surface of cells in the liver and otherorgans. The LDL receptors bind LDL and facilitate its uptake byreceptor-mediated endocytosis and subsequent delivery to lysosomes,where the LDL is degraded yielding free cholesterol for cellular use.When LDL receptors are deficient, the rate of removal of LDL from plasmadeclines, and the level of LDL rises in inverse proportions to thereceptor number. The excess plasma LDL is deposited in scavenger cellsand other cell types, producing atheromas and xanthomas. FHheterozygotes have one normal and one mutant allele at the LDL receptorlocus; hence their cells are able to bind and degrade LDL atapproximately half the normal rate. (See In: The metabolic and molecularbases of inherited disease. Seventh edition, Mac Graw-Hill, Chapter 62,Familial Hypercholesterolemia, by J. L. Goldstein et al., pp 1981-2030).

Subjects with the homozygous form of FH (incidence=1:10⁶) have plasmacholesterol levels 3-5 fold higher than normal subjects and frequentlydevelop coronary heart disease in childhood, almost invariably before 20years of age. Homozygotes possess two mutant alleles at the LDL receptorlocus, and their cells show a total or near total inability to bind ortake up LDL.

There are two animal models for FH that closely resemble the humandisease. The first is a natural mutant strain of rabbits, WatanabeHeritable Hyperlipidemic (WHHL) rabbits, and the second is the recentlyavailable mouse LDLR knock-out (LDLRKO) strain developed by Herz et al(Ishibashi, S. et al. 1993. J. Clin. Invest. 92; 883-893). Previousstudies in WHHL-rabbits have shown that homozygous animals have stronglysuppressed activity of the regulatory enzyme C7αOH (Xu et al. 1995. J.Clin. Invest. 95; 1447-1504).

In the therapy of type II-A hyperlipidemia, the strategy is based on theconcept of increasing the number of available hepatic LDL-receptorswhich in turn will reduce plasma cholesterol due to an increased hepaticuptake of LDL and LDL precursor lipoproteins, such as intermediatedensity lipoprotein, (IDL). In heterozygous FH, the most effectivetherapy is by interfering with the enterohepatic circulation of bileacids by orally administered bile acid sequestrants such ascholestyramine in combination with specific 3-hydroxy-3-methyl-glutarylcoenzyme A (HMG CoA) reductase inhibitors. An increasing number of suchdrugs (statins and vastatins) have been introduced to the market. Suchcombined therapy can reduce, but does seldom completely normalize plasmaLDL.

However, in homozygotes that do not harbor any functional LDL receptors,other means to reduce the high LDL levels must be employed. This diseasetype is a candidate for gene therapy. Such treatment has been tested inlaboratory animals using the LDLR gene and the gene encoding cholesterol7α-hydroxylase (C7αOH), the key regulatory step in the synthesis of bileacids. (Ishibashi, S. et al. 1993. J. Clin. Invest. 92, 883-893, Spady,D. K. and Cuthbert, J. A. 1995. J. Clin. Invest 96; 700-709). Theeffects are unfortunately transient. So far, the only available therapyhas been liver transplantation or plasmapheresis and/or selectiveextracorporeal removal of cholesterol-rich LDL-particles. The lattertherapy, if performed every 2-3 weeks, can reduce but not normalize theincreased plasma cholesterol level. Recently it has been shown thatcertain FH homozygotes can also benefit from high dose statin therapy(Marais, A. D et al. 1997. J. Lipid Res. 38:2071-8). Therefore, untilgene-therapy will be clinically available, there is a need of novelpharmacological therapeutic strategies in homozygous FH.

Pituitary growth hormone (GH) has several effects on cholesterol andlipid metabolism. We have previously shown that GH therapy has astimulatory effect on the hepatic LDLR expression in both rats andhumans (Rudling, M. et al. Proc. Natl. Acad. Sci. USA. 1992, 89;6983-6987), and in particular we have identified GH as an importantstimulator of the enzymatic activity of C7αOH (Rudling et al, 1997, J.Clin. Invest. 99; 2239-2245). We have shown that GH stimulates C7αOHactivity, not only in hypophysectomized animals, but also in normalyoung rats (P. Parini, et al. 1999, Cholesterol and lipoproteinmetabolism in aging: reversal of hypercholesterolemia by growth hormonetreatment in old rats, Arterioscl. Thromb. & Vasc. Biol. 19;832-839).The experiments were performed in mammals expressing normal LDLreceptors.

From “Current opinion in Lipidology”, 1997,Vol. 8, p. 337-341 by B.Angelin as well as from “Metabolism”, 1996, Vol. 45 No. 11, p. 1414-1421by Tostad et al. it was evident that familial hypercholesterolemia ofthe heterozygous form may benefit from treatment with GH because suchpatients express functional LDL receptors.

However, because homozygotes do not harbor functional LDL receptors, itwas not for a man skilled in the art obvious that the homozygous form ofthe disease may benefit from GH treatment.

DESCRIPTION OF THE INVENTION

We have now surprisingly found that administration of compounds selectedfrom GH, analogues thereof and GH-releasing compounds, optionally incombination with established lipid-lowering treatment, to mammals withfamilial hypercholesterolemia of homozygous form has beneficial effectson plasma cholesterol levels. We can show that the infusion of GH toLDLR deficient animals reduces total plasma and LDL cholesterol levels.This occurs in parallel with a normalization of a suppressed C7αOHenzymatic activity. In addition, we have also found that GH treatmentcan potentiate the effect of statins and bile acid sequestrants, twoimportant classes of lipid lowering drugs used in established treatmentof patients.

By the present invention it is also shown that GH therapy can be used toreduce plasma LDL cholesterol in FH of the homozygous form. Thus GHtreatment alone, optionally in combination with established lipidlowering treatment, can be used to treat mammals characterized by adeficiency of LDL receptors. Therefore, GH could become an adjuvant tocurrent therapy of FH-homozygotes.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to the use of compounds selected fromGH, analogues thereof and GH-releasing compounds, optionally incombination with conventional lipid lowering agents, for the preparationof a drug which reduces the serum lipids in a mammal that displays thesyndrome of FH of the homozygous form. The therapy may also be combinedwith established lipid-lowering treatment. The type of GH that can beused includes natural or recombinant GH, and variant molecules of GH oranalogues with the common denominator of ultimately being capable toactivate a GH receptor signal in cells in the species that displays thesyndrome of FH of homozygous form. One example of GH is Genotropin,which is manufactured by Pharmacia & Upjohn. Examples of analogues arecompounds that can enhance GH release or interfere with the cellularmechanisms of GH action. Compounds that cause GH release is exemplifiedby GH-releasing hormone, somatostatin-antagonists, hexarelin, and theMerck growth hormone releasing compound L-692 429. The route of GHadministration to mammals can vary and a common way of administration isby injection therapy. Alternative routes of administration may howeverbe applicable in the practice of the present invention. Such alternativeroutes for GH administration that presently exist or may be developedinclude oral, nasal, rectal and transdermal GH therapy. The dose of GHto be used for the treatment of the syndrome of FH of homozygous formmay vary dependent on the GH used and the species to be treated as wellas the clinical evaluation of a patient. In humans, GH would preferablybe injected 7 times a week but less frequent injections could be used aslong as the criteria of activating a GH receptor signal that results inreduction of cholesterol is met.

One embodiment of the present invention includes the combined treatmentwith GH and a lipid lowering therapy as LDL apheresis or with compoundspreferably selected from the list of lipid lowering drugs that includefor example statins, and bile acid sequestrants such as cholestyramine.Today there are five statins available on the market in Sweden,atorvastatin, cerivastatin, fluvastatin, pravastatin and simvastatin.

The dose ranges of these drugs will be the ones recommended by therespective suppliers for clinical use. The daily dose of human GH (suchas Genotropin) would preferably be in range from 0.02 to 0.14 IU/kgdepending on the responses obtained. The duration of treatment accordingto the present invention includes GH treatment in a continuous or in adiscontinuous fashion with or without the combination of other types oflipid lowering drugs or procedures. The duration of treatment isdependent on the judgement of the responsible physician. It ispreferable that the duration of treatment is lasting for several monthsand that the effect of treatment is monitored at least every half yearby analysis of serum cholesterol.

The syndrome of FH suitable for treatment according to the presentinvention includes homozygous LDLR mutations of any kind that result indeficient LDLR function. Such patients can be identified clinically froman elevated plasma cholesterol value. In a more refined diagnosis theLDLR gene could be sequenced or the pattern of lipoproteins determined.

This invention includes all embodiments disclosed in the appendedclaims.

In the following we provide examples that illustrate the presentinvention. These examples only serve the purpose of illustration of theinvention and are not to be considered limitations thereof.

Methods

Animals and Experimental Procedure

The studies were approved by the Institutional Animal Care and UseCommittee, Sweden. Altogether 75 male LDLRKO and 45 C57 BL/6J mice werepurchased from Bommice, Denmark. Animals were housed under standardizedconditions in groups of ten. The mice had free access to water and chow;the light cycle hours were between 6 a.m. and 6:00 p.m. At the start ofthe experiment, osmotic mini pumps containing GH were implantedsubcutaneously under light ether anesthesia. Non-GH treated animals weresham-operated. Recombinant human GH (Genotropin®), purchased fromPharmacia & Upjohn, was infused at a rate of 1.0 mg/kg per day. Aftersix days of infusion, animals where anesthetized with ether, and bloodwas collected from the eye. The mice where thereafter killed by cervicaldislocation. The livers were immediately removed and when indicated, 1 gof liver was taken for subsequent preparation of microsomes for assay ofenzyme activity as described below. The remaining liver was immediatelyfrozen in liquid nitrogen and stored at −70° C.

In the experiment comparing the effects of cholestyramine, atorvastatin,GH, and combinations thereof, animals were bled from the eye under lightether anesthesia and were not killed. Feces were collected at twooccasions during two days, the first period starting 4 days prior toinitiation of treatment and the second from day 3 to day 5 during drugtreatment. Animals were allowed to walk on a metal grid during the twodays of feces collection. Samples were collected daily and pooled.Cholestyramine (Questran™), obtained from Bristol-Myers Squibb, wasadded to ground mouse chow at a final concentration of 2%. Atorvastatin(Lipitor™) was purchased from Parke-Davies as 20 mg tablets. Groundtablets were added to ground mouse chow to a final concentration of 1500mg atorvastatin/kg ground chow. Assuming a daily food intake of 2-3 g of25 g mice this should correspond to a daily dose of 120-180 mg/kg.

The total hepatic cholesterol was determined, following extraction andsubsequent drying under nitrogen from liver samples, as described(Rudling M. J. Lipid Res. 33: 493-50 1992). Total hepatic and plasmacholesterol and plasma triglycerides were assayed using commercialavailable methods (Boehringer-Mannheim, Mannheim, Germany).

Enzymatic Activities of HMG CoA Reductase and C7αOH

Hepatic microsomes were prepared by differential ultracentrifugation ofliver homogenates in the absence of fluoride as previously described(Angelin et al 1984, J Lipid Res. 25; 1159-1166, Einarsson et al. 1986,J. Lipid Res. 27; 82-88, Einarsson et al. 1989, J. Lipid Res. 30;739-746). Microsomal HMG CoA reductase was assayed from the conversionof [¹⁴C] HMG CoA to mevalonate, and expressed as picomoles formed per mgprotein per min. The activity of C7αOH was determined from the formationof 7α-hydroxycholesterol (picomoles/mg protein/min) from endogenousmicrosomal cholesterol by the use of isotope dilution-mass spectrometryas described in detail. All enzyme assays were carried out in duplicate.

Ligand blot assay of LDL-receptors was performed using ¹²⁵I-labeledrabbit β-migrating very low density lipoprotein (VLDL), as describedpreviously (Rudling et al 1992. PNAS 89; 6983-6987). Membrane proteinswere separated by SDS-PAGE (6% poly-acrylamide). After electrotransferof proteins to nitrocellulose filters and subsequent incubation¹²⁵I-β-VLDL filters were exposed onto DuPont X-ray film at −70° C.

Size-fractionation of Lipoproteins by Fast Performance LiquidChromatography (FPLC)

Equal volumes of plasma from each animal were pooled (1-2 mL) and thedensity was adjusted to 1.21 g/mL with solid KBr. Afterultracentrifugation at 10⁵ g for 48 h, the supernatant was removed andadjusted with 0.15 M NaCl, 0.01% etylene diamine tetraacetic acid,(EDTA), 0.02% sodium azide, pH 7.3. An aliquot of this solution wasinjected on a 54×1.8 cm superose 6B column after filtration through aMillipore 0.45 mm HA filter, 2-mL fractions were collected.

Fecal Bile Acid Excretion

This was measured by the method of Beher, W. T. S. et al. 1981 Steroids.38: 281-295 as modified by Wolle et al. 1995, J.Clin. Invest. 96:260-272. Briefly, feces were collected twice for two consecutive daysand homogenized in two volumes (v/w) of water. Aliquots (correspondingto 1 g of feces) were incubated for 30 min. at 70° C., after addition of7 mL of ethanol. The mixture was filtered through a paper filter thatwas then rinsed once with 6 mL of 70° C. ethanol. After drying a 4 mLaliquot under nitrogen, 2 mL of 3M NaOH were added and samples werehydrolyzed by incubation at 100° C. for 2 h. After adjusting pH to 9,the bile acid concentration was measured in a 70 μL aliquot using afluorescence system based on resazurin.

EXAMPLE 1

Effects of GH on Plasma Lipids and Hepatic Cholesterol Metabolism

Infusion of GH to C57BL/6J and LDLRKO mice. Two sets of ten animals ofeach strain were continuously infused at a rate of 1 mg/kg/d. After sixdays of treatment, animals were killed and plasma and livers werecollected.

Total plasma cholesterol and triglycerides were increased by 250 and80%, respectively in LDLRKO animals as compared to C57BL/6J mice (FIG.1). There was also a 45% increase of total hepatic cholesterol in LDLRKOanimals. Treatment with GH clearly reduced the total plasma cholesterolin LDLRKO animals whereas no significant effect was obtained in C57BL/6Jmice. GH infusion to normal mice slightly increased total hepaticcholesterol whereas there was a slight reduction in LDLRKO animals.There was a slight but not significant reduction of total plasmatriglycerides in LDLRKO animals whereas total plasma triglycerides wereunaltered in C57BL/6J mice.

FPLC separation of plasma lipoproteins showed that the reduction ofcholesterol induced by GH in LDLRKO animals was within all sizefractions (FIG. 2), although most pronounced within VLDL and LDLparticles; the reduction in triglycerides was only within VLDL particles(FIG. 3). In C57BL/6J mice GH increased triglycerides within VLDLparticles.

The absence of LDL receptors in LDLRKO animals was confirmed by ligandblot of hepatic membranes obtained from pooled livers from each animalgroup, using β-VLDL as ligand (not shown). The expression of LDLreceptors in C57BL/6J mice was not altered by GH treatment.

To confirm this surprising finding of a plasma cholesterol loweringeffect of GH in LDLR deficient animals with pronouncedhypercholesterolemia, the previous experiment was repeated. In addition,we wanted to also determine the enzymatic activities of3-hydroxy-3-methyl-glutaryl coenzyme A, (HMG CoA) reductase, andcholesterol 7α hydroxylase, (C7αOH), being the rate limiting steps inthe synthesis of cholesterol and bile acids, respectively. Animalsreceived the same dose of GH that was infused for six days. Subsequentassay of total plasma cholesterol and triglycerides, and total hepaticcholesterol (FIG. 4) showed practically identical results, although thereduction of total plasma cholesterol was slightly less pronounced.

FPLC separation of plasma lipoproteins confirmed that GH lowered plasmalipoprotein cholesterol, particularly within VLDL and LDL particles(FIG. 5). In this experiment triglycerides were not only reduced amongVLDL particles but also within LDL and HDL particles (FIG. 6).

Assay of C7αOH activity showed a 40% increase in LDLRKO animals ascompared to C57/BL6J animals (FIG. 7). Treatment with GH clearlyincreased the activity in both animal groups (by 115 and 46% forC57/BL6J and LDLRKO mice, respectively). The enzymatic activity of HMGCoA reductase was strongly suppressed in LDLRKO animals (30% of thatfound in control C57/BL6J animals, FIG. 8). GH treatment increased theactivity of HMG CoA reductase in C57/BL6J and LDLRKO mice, by 53 and113%, respectively. Assay of the mRNA levels for C7αOH by solutionhybridization, (FIG. 9) showed a 60% reduced abundance in LDLRKOanimals, as compared to C57/BL6J animals. GH treatment increased theC7αOH mRNA level by 170% in LDLRKO mice, whereas there was a 50%reduction in the C7αOH mRNA level in C57/BL6J animals following GHtreatment.

HMG CoA reductase mRNA levels were slightly reduced in LDLRKO animalscompared to C57BL/6J animals and GH infusion increased these by 20%whereas there was no effect in C57/BL6J mice.

Thus, as in normal rats (P. Parini, et al. 1998. Cholesterol andlipoprotein metabolism in aging: reversal of hypercholesterolemia bygrowth hormone treatment in old rats. Arterioscl. Thromb. & Vasc. Biol.In press), there was no reduction of plasma cholesterol in normal micefollowing treatment with GH, which also is in line with previous resultson Sprague Dawley rats (Rudling et al, 1997, J. Clin. Invest. 99;2239-2245). GH treatment of mice also stimulated the activity of C7αOH,both in normal and LRLRKO animals. However, the activity of HMG CoAreductase was strongly suppressed in LDLRKO animals, and GH infusionincreased the activity to the same level as found in normal C57BL/6Janimals. This latter effect should theoretically strongly counteract theplasma cholesterol lowering effect of the hormone.

EXAMPLE 2

GH Treatment Potentiates the Effects of Bile Acid Sequestrants and HMGCoA Reductase Inhibitors on Plasma Lipids

To evaluate if GH treatment could have beneficial effects in combinationtherapy with established lipid lowering drugs such as statins and bileacid sequestrants, groups of 5 mice were treated with cholestyramine,atorvastatin and GH alone and in combination. After 6 days of treatment,animals were bled from the eye and assayed for cholesterol andtriglycerides.

At the doses employed there were no effects on cholesterol followingtreatment with atorvastatin or cholestyramine alone whereas there was a10% reduction following GH. Atorvastatin and GH both reduced plasmatriglycerides by approx. 20%. When GH was given in combination withcholestyramine or atorvastatin plasma cholesterol was reduced by 29 and36% respectively, and triglycerides were reduced by 34 and 43%,respectively. Combination of all three drugs resulted in the strongesteffect on plasma cholesterol, and a 43% reduction was obtained.Triglycerides were not further reduced.

Assay of the content of fecal bile acids prior to and during treatmentwith the three drugs revealed that all three drugs could increase fecalbile acids when given alone (FIG. 11). Fecal bile acids were highestwhen GH was combined with cholestyramine, whereas no further change wasobtained when GH was combined with atorvastatin or with cholestyramine.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a graph that depicts total plasma cholesterol, triglyceridesand total hepatic cholesterol in normal (C57 BL) and LDLRKO (KO) mice±GH(1 mg/kg/day) for 6 days. Each group consisted of 10 animals. Barsindicate SEM.

FIGS. 2 and 3 show the lipoprotein patterns in the four groups ofanimals described in legend to FIG. 1. Equal volumes of plasma from eachanimal were pooled and subjected to ultracentrifugation at density 1.21.The supernatant was thereafter separated on a Superose 6 column andfractionated. Total cholesterol and total triglycerides were finallydetermined and the results are presented in FIGS. 2 and 3, respectively.

FIG. 4 shows total plasma cholesterol, triglycerides and total hepaticcholesterol in normal C57 BL and LDLRKO (KO) mice±GH (1 mg/kg/day) for 6days in a repeated experiment. Each group consisted of 10 animals. Barsindicate SEM.

FIGS. 5 and 6 demonstrate the lipoprotein patterns (cholesterol andtriglycerides) in the four groups of animals described in legend to FIG.4 after separation of pooled plasma by FPLC.

FIG. 7 shows the enzymatic activity of C7αOH in microsomes prepared frompooled liver samples of the four groups of animals described in legendto FIG. 4. The means and standard error of means from three separatepools of all animals are shown.

FIG. 8 shows the enzymatic activity of HMG CoA reductase in microsomesprepared from pooled liver samples of the four groups of animalsdescribed in legend to FIG. 4. The means and standard error of meansfrom three separate pools of all animals are shown.

FIG. 9 shows the mRNA abundance for the LDLR, HMG CoA reductase andC7αOH determined by solution hybridization. Total nucleic acids wereextracted from a sample of liver from each individual and incubated withthe respective complementary radio-labeled cRNA probe.

FIGS. 10 and 11 show the total plasma cholesterol and triglyceridelevels and the fecal bile acid content in LDLRKO mice following 6 daysof treatment with cholestyramine, atorvastatin and GH. The three drugswere given alone or in the indicated combinations to groups of 5 mice atdoses described below under methods; Animals and experimental procedure.After 6 days of treatment animals were bled from the eye under lightether anesthesia for the determination of total cholesterol andtriglycerides, (FIG. 10). Feces was collected during two days at twooccasions; the first occasion starting 4 days prior to initiation oftreatment (FIG. 11, open bars) and from day 3 to day 5 during drugtreatment (FIG. 11, filled bars).

What is claimed is:
 1. A method for the treatment of a mammal withfamilial hypercholesterolemia of homozygous form comprisingadministering to said mammal a therapeutically effective amount ofgrowth hormone or a prevalent amount of a growth hormone releasingcompound selected from the group growth-hormone releasing hormone,somatostatin-antagonists, hexarelin and Merck growth hormone releasingcompound L-692 429, wherein the administered amount is effective totreat a mammal with familial hypercholesterolemia.
 2. A method for thetreatment of a mammal with familial hypercholesterolemia of homozygousform comprising administering a compound as disclosed in claim 1 incombination with a lipid-lowering agent selected from the groupconsisting of 3-hydroxy-3-methyl-glutaryl coenzyme A reductaseinhibitors and bile acid sequestrants.
 3. A method for the treatment ofa mammal with familial hypercholesterolemia of homozygous form accordingto claim 2 comprising the administering of growth hormone andcholestyramine.
 4. A method for the treatment of a mammal with familialhypercholesterolemia of homozygous form according to claim 2 comprisingthe administering of growth hormone and statins.
 5. A method for thetreatment of a mammal with familial hypercholesterolemia of homozygousform according to claim 4 comprising the administering of growth hormoneand atorvastatin.
 6. A method for the treatment of a mammal withfamilial hypercholesterolemia of homozygous form according to claim 2comprising the administering of growth hormone, cholestyramine andatorvastatin.
 7. A method for the treatment of a mammal with familialhypercholesterolemia of homozygous form according to claim 1 comprisingthe administering of growth hormone in natural or recombinant form.
 8. Amethod for the treatment of a mammal with familial hypercholesterolemiaof homozygous form according to claim 1 comprising the administering offrom 0.02 to 0.14 IU per kilo body weight per day of growth hormone.